Adobe Flash came under fire this week from two tech titans looking to crack down on the software after years of problematic behavior. Facebook and Mozilla, the company behind the Firefox browser, both made moves to force out Flash, insisting that Adobe needs to patch its many security holes or abandon the software altogether.

Facebook security chief Alex Stamos came out swinging Sunday with a tweet saying, "It is time for Adobe to announce the end-of-life date for Flash." Late Monday night, Mozilla's support chief Mark Schmidt declared on Twitter, "BIG NEWS!! All versions of Flash are blocked by default in Firefox as of now."

Flash, they argue, represents one of the biggest vulnerabilities on the Internet. For example, it came to light last week that the spyware-for-hire firm Hacking Team relied on weaknesses in Flash to infiltrate computers and deploy malware.

A decade ago, Adobe Flash was an essential part of online life. Most streaming videos, online games, and spiffy websites required Flash to work. But bugs and security problems have plagued the software and soured many people's opinion of it.

Apple's late founder Steve Jobs took one of the most memorable stands against Flash in 2010. He published an open letter railing against the software for being buggy, backward looking, and a battery hog. "Flash is the number one reason Macs crash," he wrote. "We don’t want to reduce the reliability and security of our iPhones, iPods and iPads by adding Flash."

Adobe regularly issues updates to Flash that attempt to fix vulnerabilities, but public opinion has slipped away from it. YouTube ditched Flash in January, opting instead for the non-proprietary HTML5. Google's Chrome browser has not blocked Flash by default (as Firefox has), but it now automatically stops some instances of Flash video.

Mr. Schmidt says that Mozilla is willing to welcome Flash back into the fold – after all, Flash still runs on 10.6 percent of all websites, according to W3Techs – but Mozilla needs to see some major improvements first.

To be clear, Flash is only blocked until Adobe releases a version which isn't being actively exploited by publicly known vulnerabilities.